[NAT] - Source and destination

[Vivien FRANCOIS]

Hi,

Considering the below network, I am trying to accomplish the communication in green arrows for the request (telnet on port 80) and orange for the reply from the server. Router R1 should NAT communication as indicated by the source (S) and destination (D) labels below the green arrow. I've posted relevant parts of R1's config that should NAT the source and destination of the packet. Yet, when packet exits R1 toward the web server packet is still sourced from 192.168.0.1 although it should be "NATted" and sourced by Ge0's address IP (10.0.0.1). Problem is that as the server sees packet from 192.168.0.1 instead of 10.0.0.1 it does not send it back to R1.

I've posted an output of a debug ip nat on R1 which shows that source isn't translated and also a show ip accces-list which shows that ACL 1 never matches.

Main constraint is that configurations of R2 and WS1 cannot be changed.

Note : routers are running IOS 150-1

I am wondering what I am missing in R1's config that will translate packet's source IP address. Any help would be appreciated.

Thanks in advance.

[blau grana · Accepted solution]

Hi Vivien

Today I was dealing with same problem as you.

Here is solution also with explanation:

http://blog.ine.com/2008/02/15/the-inside-and-outside-of-nat/

[Vivien FRANCOIS]

Hi,

Thank you very much for the link I was able to adapt what's exposed in the blog for my configuration and get it to work in my initial topology. Below is the solution if somebody looks for it.

Here are routes on router R1:

ip route 10.0.0.5 255.255.255.255 192.168.0.1

ip route 192.168.0.1 255.255.255.255 172.16.0.1

ip route 198.19.255.0 255.255.255.0 Null0

ip route 198.19.255.3 255.255.255.255 10.0.0.2

And here are NATs:

ip nat inside source static 198.18.0.1 10.0.0.5

ip nat outside source static 10.0.0.2 198.19.255.3

Thanks again for the very useful link.

Vivien F.

Message was edited by: Vivien FRANCOIS